Production of containers

ABSTRACT

A container has a peripheral wall defined by a single preformed blank of flexible sheet material and provided with axially extending injection moulded ribs, one of which forms a seam uniting juxtaposed opposite edge portions of the piece of flexible sheet material, and at least one circumferentially extending injection moulded rib. One end of the zone bounded by the peripheral wall is closed by an end closure formed of injection moulded material or flexible sheet material. The container is formed in a container shaped mould cavity which constrains the sheet material to the required shape while the ribs and end closure are being injection moulded simultaneously.

[451 Sept. 17, 1974 1 PRODUCTION OF CONTAINERS [75] Inventor: Brian Leo Chudleigh Sutch, Great Bookham, England [73] Assignee: Airfix Industries Limited, London,

England [22] Filed: Jan. 26, 1972 [21] Appl. No.: 220,964

[30] Foreign Application Priority Data [58] Field of Search 229/l.5 B; 220/72; 150/.5; 264/251, 252, 254, 259, 261

[56] References Cited UNITED STATES PATENTS 2,409,958 10/1946 Rogers.... 264/261 X 3,169,688 2/l965 Schad 229/l.5 B

Schwartz 229/l.5 B Shattuck 264/26l 2/1965 ll/l969 Primary Examiner-Donald F. Norton Attorney, Agent, or FirmScrivener, Parker, Scrivener & Clarke [5 7 ABSTRACT A container has a peripheral wall defined by a single preformed blank of flexible sheet material and provided with axially extending injection moulded ribs, one of which forms a seam uniting juxtaposed opposite edge portions of the piece of flexible sheet material, and at least one circumferentially extending injection moulded rib. One end of the zone bounded by the peripheral wall is closed by an end closure formed of injection moulded material or flexible sheet material. The container is formed in a container shaped mould cavity which constrains the sheet material to the required shape while the ribs and end closure are being injection moulded simultaneously.

7 Claims, 2 Drawing Figures PRODUCTION OF CONTAINERS I This invention is concerned with improvements in and relating to the production of composite flexible sheet material and injection moulded containers, for example as disclosed in US. Pat. application No. 123,777 filed on 12 Mar. 1971 in the names of Sutch and Coggan now abandoned in favor of Ser. No. 355,288 filed Apr. 27, l973 and assigned to the same assignee as the present application.

It has been proposed to make a container using flexible sheet material which forms the peripheral wall of the container and to scam that wall by injection moulding. This produces a container which is satisfactory for many purposes. However, such a container may not have adequate strength in compression such as might occur in stacking filled containers.

According to one aspect of this invention there is provided a container having a peripheral wall of preformed flexiblesheet material, a closure closing one end of the zone bounded by the peripheral wall, a plurality of axially extending ribs injection moulded on to the sheet material and extending from the one closed end of the peripheral wall towards the other end and a circumferentially extending rib injection moulded on to the sheet material of the peripheral wall intermediate the ends of the peripheral wall.

According to another aspect there is provided a method of making a container having a peripheral wall formed of flexible sheet material and a closure closing one end of the zone bounded by the peripheral wall, the method comprising the steps of inserting a piece of flexible sheet material into a mould cavity defining a peripheral wall provided with axially extending ribs and a circumferentially extending rib and an end closure,

the sheet material being positioned in the peripheral wall defining part of the cavity with juxtaposed opposite edge portions at one axially extending rib defining cavity, and injecting mouldable material into the cavity to form said ribs which when the sheet material is removed from the cavity will constrain the sheet material to the container shape.

Features and advantages of this invention will appear from the following description of one embodiment thereof, given by way of example only, reference being had to the accompanying drawings in which:

FIG. 1 is a section through a container in a plane including the axis of the container, and

FIG. 2 is a section through a mould for making the container with the flexible sheet material in place.

The container 1 comprises a peripheral wall defined by a single preformed blank of flexible sheet material 2 whose opposite edges are juxtaposed and united by an axially extending injection moulded rib 3. The peripheral wall is also provided with further axially extending injection moulded ribs 3 and a circumferentially extending rib 5. The peripheral wall bounds a zone of cross-section which decreases towards one end which is closed by an injection moulded end closure 4. The other end of the peripheral wall is provided with an injection moulded lip 7. The container is made by axially feeding the piece of sheet material into a cavity 6 of a female mould-member 7, as by wrapping it about a spigot, holding it there by vacuum, advancing the spigot into the cavity, releasing the vacuum and withdrawing the spigot, for example as described in US. Pat. application No. 160,469 filed on 7th July 1971 in the name of Sutch now abandoned in favor of Ser. No. 364,091 filed May 25, 1973 and assigned to the same assignee as the present application.

The foil is trapped in the mould cavity defined between a male mould member 8, advanced into the cavity, and the female member. The mould cavity includes an annular peripheral wall defining cavity part occupied by the sheet material and an end closure defining cavity part 9.

Each of the axially extending rib defining cavity parts comprises a channel 10 in the male member and a channel 10a in the female member, these channels tapering oppositely in radial thickness to either side of the annular cavity part. A, or each, of a number of circumferential rib defining cavity parts 11 is of parallelogram section, the opposed radially directed sides of the parallelogram having a lesser inclination to the axis of the cavity than adjacent parts of the annular cavity. As shown they are parallel to the axis of the cavity. The annular cavity is stepped at the region of the or each peripheral rib cavity. A lip defining cavity part 12 defines the lip 7. When material is injected at the end closure cavity part it travels up the inside of the sheet material in channels 10 forcing the material outwardly into channels 10a and also fills the or each peripheral rib cavity and the lip cavity. The sheet material is positioned in the cavity with juxtaposed opposite edges in one of the axial rib cavity parts, the edges being united by that injection moulded rib.

Instead of using a spigot to feed the foil to the mould, the male member may be used, suitable passages being provided in that member for coupling to a vacuum source.

In another arrangement the foil may be fed into an intermediate cavity radially through a slot in the cavity wall and thence pushed axially into the mould cavity, for example as described in US. application Ser. No. 186,229 filed on 4th Oct. 1971, now US. Pat. No. 3,780,559, in the name of Turner and assigned to the same assignee as the present application.

Whilst a circular section frusto conical container has been described, the invention is also applicable to polygonal section containers. Whilst the base has been described as injection moulded, it may be formed by a piece of flexible sheet material, or by one or more panels of sheet material connected integrally to the peripheral wall sheet material.

The sheet material may be a synthetic plastics or metal foil, paper, braid or any suitable coated, laminated or composite flexible sheet material whether pervious or impervious. Where the specification and claims refer to a preformed blank this term is not limited to a preshaped blank but is intended to define a blank separately made or preformed prior to being inserted into the mould where the axial and peripheral ribs are united with the preformed blank as a unitary moulding.

What is claimed is:

1. A container comprising flexible sheet material defining a peripheral wall, a closure closing one end of the zone bounded by the peripheral wall, said flexible sheet material having, juxtaposed axially extending opposite edge portions, a unitary moulding formed on the surface of said sheet material and comprising a plurality of ribs extending axially from the one closed end of the peripheral wall towards the other and a circumferentially extending rib intermediate the ends of the axially extending ribs, each edge portion of said flexible sheet material being united to a juxtaposed opposite edge portion by one of said ribs defining a seam between the edge portions.

2. A container according to claim 1 wherein the zone bounded by the peripheral wall has a cross-section which decreases towards the closed end thereof and the circumferential rib has an inwardly facing surface which has an inclination to the axis of the container less than the inclination of adjacent portions of the peripheral wall to the axis.

3. A container according to claim 1 wherein the zone bounded by the peripheral wall has a cross-section which decreases towards the closed end thereof and the circumferential rib has an outwardly facing surface which has an inclination to the axis of the container less than the inclination of adjacent portions of the peripheral wall to the axis.

4. A container according to claim 1 wherein the peripheral wall has a cross-section which decreases towards the closed end thereof and the circumferential rib has inwardly and outwardly facing surfaces which have equal inclinations to the axis of the container less than the inclination of adjacent portions of the peripheral wall to the axis.

5. A container according to claim 4 wherein the axially extending ribs extend to the other end of the peripheral wall, the edge portions of the sheet material at the other end of the peripheral wall being provided with an injection moulded lip, the axially extending ribs, circumferentially extending rib and lip defining therebetween panels of flexible sheet material.

6. A container according to claim 5 wherein said ribs are formed on the inner surface of the sheet material of the peripheral wall.

7. A container according to claim 5 wherein said ribs are formed on the outer surface of the sheet material of the peripheral wall. 

1. A container comprising flexible sheet material defining a peripheral wall, a closure closing one end of the zone bounded by the peripheral wall, said flexible sheet material having juxtaposed axially extending opposite edge portions, a unitary moulding formed on the surface of said sheeT material and comprising a plurality of ribs extending axially from the one closed end of the peripheral wall towards the other and a circumferentially extending rib intermediate the ends of the axially extending ribs, each edge portion of said flexible sheet material being united to a juxtaposed opposite edge portion by one of said ribs defining a seam between the edge portions.
 2. A container according to claim 1 wherein the zone bounded by the peripheral wall has a cross-section which decreases towards the closed end thereof and the circumferential rib has an inwardly facing surface which has an inclination to the axis of the container less than the inclination of adjacent portions of the peripheral wall to the axis.
 3. A container according to claim 1 wherein the zone bounded by the peripheral wall has a cross-section which decreases towards the closed end thereof and the circumferential rib has an outwardly facing surface which has an inclination to the axis of the container less than the inclination of adjacent portions of the peripheral wall to the axis.
 4. A container according to claim 1 wherein the peripheral wall has a cross-section which decreases towards the closed end thereof and the circumferential rib has inwardly and outwardly facing surfaces which have equal inclinations to the axis of the container less than the inclination of adjacent portions of the peripheral wall to the axis.
 5. A container according to claim 4 wherein the axially extending ribs extend to the other end of the peripheral wall, the edge portions of the sheet material at the other end of the peripheral wall being provided with an injection moulded lip, the axially extending ribs, circumferentially extending rib and lip defining therebetween panels of flexible sheet material.
 6. A container according to claim 5 wherein said ribs are formed on the inner surface of the sheet material of the peripheral wall.
 7. A container according to claim 5 wherein said ribs are formed on the outer surface of the sheet material of the peripheral wall. 